Apache Cassandra Maintenance Tasks

Anti-Entropy Maintenance

The Apache Cassandra ring nodes require periodic maintenance to ensure consistency across all
nodes. To perform this maintenance, use the Cassandra "nodetool -h localhost repair" command.

Note: This maintenance must be run on every Cassandra node at least every seven days in
order to eliminate problems related to Cassandra "forgotten deletes". Running "nodetool -h localhost repair " imposes a
significant load on the system, so Apigee recommends that this process only be run during
periods of relatively low workload.

You should also run the command on one Cassandra node at a time. You can run it on different
nodes on different days, or schedule it so that there are several hours between running it on
each node.

In a single-region or single-data-center Apigee installation, use the command "nodetool -h localhost repair " on one
Cassandra node to ensure consistency across all nodes in the ring. In a multi-region or
multi-data-center Apigee installation, use "nodetool -h localhost repair -pr" on every
node in the ring (across all regions or data centers).

For more information on "forgotten deletes" and Cassandra consistency, and for instructions on
how to use "nodetool", see:

Important Note: Apigee does not recommend adding, moving or removing
Cassandra nodes without contacting Apigee Customer Success. The Apigee system tracks Cassandra
nodes using their IP address, and performing ring maintenance without performing corresponding
updates on the Apigee environment metadata will cause undesirable results.

Log File Maintenance

Cassandra logs are stored in the /opt/apigee/var/log/cassandra directory on
each node. By default, a maximum of 50 log files, each with a maximum size of 20 MB, can be
created; once this limit is reached older logs are deleted when newer logs are created.

If you should find that Cassandra log files are taking up excessive space, you can modify the
amount of space allocated for log files by editing the log4j settings.

Edit /opt/apigee/customer/application/cassandra.properties
to set the following properties. If that file does not exist, create it:conf_log4j-server_log4j.appender.r.maxfilesize=20MB
# max file size
conf_log4j-server_log4j.appender.r.maxbackupindex=50 # max open files

Restart Cassandra by using the commands:$
/opt/apigee/apigee-service/bin/apigee-service apigee-cassandra restart